“In order to hear a vocalist properly, it is important that his/her voice “loudness” be properly balanced relative to the music. If not loud enough, we won’t hear what they’re singing and if too loud, the music will sound “thin” Although it may seem simple to adjust the singer’s volume to match the music, it is not because some singers sing with wide “dynamic range” (it’s the difference between their loudest voice and their softest voice) and depending on the type of music they sing along, their softest voice may be totally “buried” under the music. The “busiest” the music is, the harder it gets (i.e. music having many instruments playing together will burry soft voice passage more than if only a single guitar is playing) There’s a whole science about this phenomena (psychoacoustics)
They’re basically two ways to fix this dynamic range issue: 1-vocal technique 2-compressors/limiters (They can also be combined together if desired)
– The standard technique to produce consistent volume into a microphone is for the singer to back off from the mic when singing loudly and get closer to the mic when singing softly. This technique is mostly important when singing into sound systems that don’t uses compressor/limiters, such as in small live clubs. Otherwise,good singers (such as Bublé) will overload the sound system (produce distortion) when singing loudly. The sound engineer could also lower the mic volume to prevent overload but then the soft passages would be buried under the music
However, ALL professional sound systems used in TV/Recording studios (including XFactor’s) use comp/limiters and they allow singers not to worry too much about their microphone technique as they will prevent any sound overloads (even if they would scream their hearts out directly into the mics) What these comp/limiters also do is allow picking up sounds that are relatively very far from the singer (like when Bublé moves away from the mic) and make them sound almost as loud as if the singer was singing up-close.
What comp/limiters cannot do is to compensate for frequency response changes resulting from microphone position relative to the vocalist (typically, the more closer/in-line with the mic the singer is, the more “bassy” and “brighter” it will sound. The further away/off-axis it is the more “midrange” it will sound.
What tells me Bublé was singing live is anytime he turns is head away from the mic (such as when he shouts “woaaa”) If you hear closely, you will hear his voice loose “brightness” (or if you prefer “treble”, “highs”) and that is definite side-effect of singing off-axis to a directional mic.”
